It depends on what you are cooking as each oil will inevitably carry some flavor but smoke point is really where you need to be concerned. For example olive oil is not a good frying oil, although you can use it if you are careful. For highest smoke point go with grape seed. But for Asian flavors peanut oil is not a bad thing---especially when combined with a little chile oil.

Both of the previous answers answer your question, plus raise valid points. Canola oil expensive? Where are you shopping? Go with grapeseed if you're looking for highest smoke point. That would then be followed by palm oil then peanut. Go with peanut if you're looking for it to impart a particular flavor. Go with grapeseed if you're more concerned about your health, that would be followed by canola

I'd go with peanut, myself, assuming you're doing home cooking and have no one with allergy issues in the household. Canola works alright and is the least expensive option, but it has a fishy smell when heated (from the linoleic acid in the oil) that can be detectable in the fried food and definitely lingers around the house, post-frying.

Grapeseed oil is indeed an excellent choice for high-temperature cooking because of its high smoke point, but at $10 for 16 ounces where I shop, I'm not going to fill a fryer with it.